In the past, various geographic information services that present to a user geographic information in the real world on a computer screen have been put into practical use. For example, through the use of common map retrieval services opened to the public on the Web, a user can easily obtain a map of a region including locations corresponding to desired place-names, addresses, or names of landmarks, etc. On any maps displayed in map retrieval services, it is also possible to place a mark on each facility that complies with the keyword designated by a user.
Further, recent dramatic advances in computer performance have enabled user terminals to process not only 2-dimensional planar maps but also information regarding 3-dimensional spaces. For example, the following PTL1 discloses a method of partially processing an input image and displaying a target object such as a building or a facility in a 3-dimensional space shown in the input image in an emphatic manner so that the target object can be easily found in the real world.